Naloxone has the following structure and is synthesized from thebaine:

Naloxone is most commonly used to treat patients suffering from opioid dependence or overdose because it is a competitive μ-opioid antagonist that blocks the effects of opioids. Naloxone is currently available in Suboxone® (Suboxone is a registered trademark of Reckitt Benckiser Healthcare (UK) Limited) as tablet or sublingual film strip formulations. Suboxone® contains buprenorphine and naloxone in a 4:1 ratio.
One issue with other opioid dependence treatments is that they can become addictive. Naloxone, however, does not appear to be addictive and patients do not build up a tolerance.
Naloxone has also been used as a treatment for cognitive insensitivity to pain with anhidrosis. Insensitivity to pain with cognitive anhidrosis is a disorder in which the patient cannot feel pain.
Naloxone may be administered orally, intravenously, by injection or via the nasal mucosa. Naloxone has a low mean serum half-life when administered parentally. The quick metabolism may require repeat dosing or cause patient discomfort between doses. Enteral administration has low bioavailability due to hepatic first pass metabolism.
Accordingly, while there are some naloxone formulations currently available, there is a need for safe and effective sublingual spray formulations that are storage stable and contain naloxone, pharmaceutically acceptable salts or a derivative thereof.